The present invention relates to a control unit and a control method for a car loading an automatic transmission and more particularly to a control unit and a control method suited to a car including a synchronizer type transmission having a plurality of gears and a plurality of synchronizer capable of transferring torque from the input shaft to the output shaft as an automatic transmission.
Recently, as a system having a clutch and gear change which are automated using a synchronizer type transmission used for a manual transmission, an automated manual transmission (hereinafter referred to as an automatic MT) has been developed. However, under control by a conventional automatic MT for shifting, the drive torque is interrupted by the clutch disengaging and engaging operation, and the shift quality is degraded, and a sense of incompatibility may be given to a crewman.
Therefore, for example, as described in Japanese Laid-open Patent Publication No. 2001-213201, a method for, when changing the first connection to the second connection, transferring the engine torque from the input shaft to the output shaft by the synchronizer of one selected synchronizer and canceling the interruption of the driving torque is known. By this method, the transfer path formed by the first connection is switched to the transfer path formed by the synchronizer, and then the transfer path formed by the synchronizer is switched to the transfer path formed by the second connection to shift the gear, thus the interruption of the driving torque is canceled and the degradation of the shift quality is prevented.